Dynamic logging and prioritization of error incident data

ABSTRACT

Aspects of the invention include receiving an error code describing a computer hardware or firmware error. A list of data items to be collected to assist in correcting the error is received. The contents of the list are selected based at least in part on the error code and are in priority order. The data items in the list are collected and a buffer to store the collected data items is selected. At least a subset of the collected data items to be written is transmitted to the buffer. All of the collected data items are transmitted to the buffer when the buffer is large enough to hold all of the data items in the list. A subset of the collected data items are transmitted to the buffer in priority order when the buffer is not large enough to hold all of the data in the list.

DOMESTIC PRIORITY

This application is a continuation of U.S. patent application Ser. No.16/565,619, filed Sep. 10, 2019, the content of which is incorporated byreference herein in its entirety.

BACKGROUND

The present invention generally relates to logging data related tohardware or firmware errors, and more specifically, to dynamic loggingand prioritization of error incident data.

When a computer system encounters a hardware or firmware error, dataneeds to be collected to analyze the nature of the error. This can beperformed by collecting the relevant hardware and firmware stats. Oncethe data items are collected, a fixed size area of system memory,referred to as a log buffer, is used to store the data items for futureanalysis. Depending on the nature of the error, a variable amount ofdata may be required to be logged.

Errors in hardware and embedded firmware systems can require a varietyof data for problem identification. The data required may be unique anddependent on content of hardware error registers. The system firmwarecan determine an error has occurred based, for example, oninconsistencies in control structures and/or contents hardwareregisters. The mechanisms a system can use to gather error data forsubsequent analysis may be limited due to system constraints. Forexample, the time allotted to perform data collection may be limited dueto timing requirements in real time systems. Another example is that thesize of the incident data may be limited based on an amount of storagespace available for the data.

SUMMARY

Embodiments of the present invention are directed to dynamic logging andprioritization of error incident data. A non-limiting examplecomputer-implemented method includes receiving an error code describinga computer hardware or firmware error. A list of data items to becollected to assist in correcting the error is received. The contents ofthe list are selected based at least in part on the error code, and thecontents of the list are in priority order from a highest priority dataitem to a lowest priority data item. The data items in the list arecollected and a buffer to store the collected data items is selected. Atleast a subset of the collected data items to be written is transmittedto the buffer. All of the collected data items are transmitted to thebuffer when the buffer is large enough to hold all of the data items inthe list, and a subset of the collected data items are transmitted tothe buffer in priority order starting with the highest priority dataitem when the buffer is not large enough to hold all of the data in thelist.

Other embodiments of the present invention implement features of theabove-described method in computer systems and computer programproducts.

Additional technical features and benefits are realized through thetechniques of the present invention. Embodiments and aspects of theinvention are described in detail herein and are considered a part ofthe claimed subject matter. For a better understanding, refer to thedetailed description and to the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The specifics of the exclusive rights described herein are particularlypointed out and distinctly claimed in the claims at the conclusion ofthe specification. The foregoing and other features and advantages ofthe embodiments of the invention are apparent from the followingdetailed description taken in conjunction with the accompanying drawingsin which:

FIG. 1 depicts a system for dynamic logging and prioritization of errorincident data in accordance with one or more embodiments of the presentinvention;

FIG. 2 depicts a service element containing log buffers in accordancewith one or more embodiments of the present invention;

FIG. 3 depicts a block diagram that includes a logging reference tableand logging tables in accordance with one or more embodiments of thepresent invention;

FIG. 4 depicts a block diagram that includes logging tables, datastructures, and a firmware function in accordance with one or moreembodiments of the present invention;

FIG. 5 depicts a linked list of data structures in accordance with oneor more embodiments of the present invention;

FIG. 6 depicts a process flow diagram of dynamic logging andprioritization of error incident data in accordance with one or moreembodiments of the present invention;

FIG. 7 depicts a process flow diagram of transferring log data to aservice element in accordance with one or more embodiments of thepresent invention;

FIG. 8 depicts a process flow diagram of post processing queued logentries in accordance with one or more embodiments of the presentinvention;

FIG. 9 depicts a cloud computing environment according to one or moreembodiments of the present invention;

FIG. 10 depicts abstraction model layers according to one or moreembodiments of the present invention; and

FIG. 11 illustrates a system for buffer overflow trapping according toone or more embodiments of the present invention.

The diagrams depicted herein are illustrative. There can be manyvariations to the diagrams, or the operations described therein withoutdeparting from the spirit of the invention. For instance, the actionscan be performed in a differing order or actions can be added, deletedor modified. Also, the term “coupled”, and variations thereof describeshaving a communications path between two elements and does not imply adirect connection between the elements with no interveningelements/connections between them. All of these variations areconsidered a part of the specification.

DETAILED DESCRIPTION

One or more embodiments of the present invention provide an intelligentmechanism for collecting data for use in debugging hardware and firmwareerrors. The content of the data collected can be dynamically determinedbased on indicators presented by hardware registers and/or by codevalues provided by firmware. The error data collection is performed bydedicated firmware, referred to herein as an error logging mechanismthat builds a prioritized linked list of elements, or data items, to becollected. The data items in the prioritized linked list can vary basedon the nature of the error detected.

In accordance with one or more embodiments of the present invention, theerror logging mechanism dynamically determines at the time of errordetection what size buffer will be needed to store the collected data,or log data. Based on that decision, the error logging mechanismattempts to allocate a buffer from the appropriate buffer pool. If alarge buffer in a pool of larger sized buffers is needed but cannot beallocated, the error logging mechanism attempts to allocate a log bufferfrom a pool of smaller sized buffers. When a buffer that is smaller thanthe determined size of the log data is used, some not all of the logdata may be lost. One or more embodiments of the present inventionaddress this by logging the highest priority data first. The log buffersin buffer pools that include log buffers of different sizes are referredto herein collectively as enhanced log buffers. If there are no enhancedlog buffers available, the error logging mechanism defaults back totraditional logging methods.

In accordance with one or more embodiments of the present invention, thebuffer pool is located on a system, referred to herein as a serviceelement, remote from the error logging mechanism which is executing on aserver. The error logging mechanism generates a log (also referred toherein as “collected data”) that needs to be transferred to the serviceelement, however in some cases the service element may not be able toprocess the log at the time that the error is detected and the log isgenerated. One or more embodiments of the present invention are capableof handling this issue by allowing the error logging mechanism tocontinue with log generation and eventually transfer all the logs thatit has generated to the remote system in the correct order once theremote system (e.g., the service element) is ready to accept the pendinglogs.

Examples of hardware errors include, but are not limited to processorerrors; first-in first-out (FIFO) errors; and Peripheral ComponentInterconnect Express (PCIe) errors. Examples of processor errors caninclude, but are not limited to: an attempt to execute an illegalinstruction; an attempt to access a storage location that isunavailable; an attempt to access storage with an effective addressalignment that is invalid for the instruction; and the execution of adefined instruction using an invalid form. Examples of FIFO error caninclude, but are not limited to: overflow errors, underflow errors, andread/write errors. An example of a PCIe error includes, but is notlimited to reception of a fatal transaction layer packet (TLP). As knownin the art, firmware refers to computer code that is programed intohardware components to control their operation and to provide aninterface between an operating system and the hardware components.Examples of firmware errors include, but are not limited to: failedfirmware state machine transitions; detection of inconsistencies incontrol block fields such as unknown/undefined values; and timeouts forprocess blocking commands (e.g., blocked threads waiting for anasynchronous process to complete which exceeds the allotted time,essentially a deadlocked thread).

One or more embodiments of the present invention provide technologicalimprovements over current methods of logging error data that may limitthe amount of data that may be collected when an error is detected andthat may result in incomplete information about the error beingcollected. A disadvantage of contemporary approaches is that theinformation helpful for determining a cause of the detected error maynot be captured. This can lead to extending the amount of time that ittakes to discover a root cause of the detected error. One or moreembodiments of the present invention provide technical solutions to oneor more of these disadvantages by providing different sized log buffersthat can be selected based on characteristics of the error that isdetected. In this manner, more information can be collected and loggedabout particular errors (e.g., based on their error codes). One or moreembodiments of the present invention also provide technical solutions toone or more of these disadvantages by collecting the data items to belogged in a prioritized order so that information thought to be mosthelpful to determining the root cause of an error is collected first. Inthis manner, if some of the information is not stored in a log bufferdue, for example to a large enough log buffer not being available and/orto not enough time being available to capture all of the log data, themost important information is stored in the log buffer. This provides ahigher likelihood that the data needed for determining the cause of theerror is available in the log buffer for analysis.

One or more embodiments of the present invention provide technologicalimprovements over current methods of logging error data that may collectlarge volumes of the same data items for every error. A disadvantage ofcontemporary methods is that the same data may not apply to every typeof error and this can result in using computer resources to collect,transmit, and store unnecessary data. One or more embodiments of thepresent invention provide technical solutions to this disadvantage bydynamically varying the amount and type of data collected based on anerror code(s) associated with the detected error. In this manner, when aparticular error is detected, only data that is identified as beinghelpful to determine that cause of the particular error is collected.This can result in using fewer computer resources such as those used tocollect and store the log data, or error data, and fewer networkresources to transmit the error data. This can also result in betterutilization of what may be a limited amount of log buffers in theservice element. In addition, the order of importance of particular dataitems may be different for different error codes.

One or more embodiments of the present invention allow for logginginformation about an embedded system error in a way that is specific forthat error. The highest importance data is stored first followed byadditional data in descending priority order. This ensures that ifnecessary, only the least important data items are discarded.

One or more embodiments of the present invention also provide that datacollection for different errors be unique and dynamically defined basedon the type of error for more effective debugging of the error.

Turning now to FIG. 1, a system 100 for dynamic logging andprioritization of error incident data is generally shown in accordancewith one or more embodiments of the present invention. In accordancewith one or more embodiments of the present invention, all or a portionof the system 100 is located at a customer location. In accordance withone or more embodiments of the present invention, all or a portion ofthe system 100 is located in a cloud computing environment.

The system 100 shown in FIG. 1 includes a service element 102, a network104, a server 106, a storage area network (SAN) 108, and storage devices110. In accordance with one or more embodiments of the presentinvention, the server 106 includes a hypervisor 116 for executingmultiple operating systems (OSs) 118. The server may be implemented byany computer server known in the art such as, but not limited to, anIBM® System z®. The hypervisor 116 interacts with an input/output (I/O)subsystem 114 to access data on the storage devices 110 via host busadapters (HBAs) 112 and the SAN 108. As shown in FIG. 1, each HBA 112includes an error logging mechanism 120 that collects error data when anerror is detecting during an access to one of the storage devices 110.In accordance with one or more embodiments of the present invention, theservice element 102 includes buffers for storing error data collected bythe error logging mechanism 120. The data stored in the service element102 can be used by the customer and/or sent to a computer or serviceprovider to debug errors that are detected in the system 100. Thenetwork 104 can be implemented by any wired or wireless network known inthe art such as, but not limited to: an Ethernet network and a networkin a cloud computing environment.

In accordance with one or more embodiments of the present invention, theerror logging mechanism 120 is part of an embedded system located ineach HBA 112 for detecting and correcting firmware and hardware errors.As known in the art, each embedded system can include applicationspecific hardware such as a hardware state machine and firmware forcontrolling the hardware state machines in real time.

The hardware state machines may have dedicated hardware for checking forvalid state transitions. In addition the data paths within the hardwaremay have error checking including, but not limited to, parity checkingand error correction code support to ensure the integrity of the dataflowing through the system. If the hardware state machine detects anerror, it may be able to correct it without interaction with thefirmware. In this case, statistics may be kept and the firmware may bemade aware only upon request or when some threshold is reached.Alternatively, the nature of the error may be such that the hardwarestate machines may have to stop processing and alert the firmware forrecovery actions. In such a condition, there may be a large amount ofinformation that can be collected from the hardware. The actual amountof information that is collected can be limited by resources availableto perform the logging as well as the time allotted to perform thelogging.

The firmware of the embedded systems can also check for consistency incontrol structures. These control structures may be manipulated by thefirmware, the hardware, and possibly entities outside of the embeddedsystem. An indication can be developed by the firmware as to the natureof the error and the nature of the error can be summarized by thefirmware as a bit vector reason code.

For both errors detected by the hardware and errors detected by thefirmware, vast amounts of state information can be available for loggingand it is not feasible to collect all of the available state informationdue to, for example, system constraints for time and an amount of storedrequired to collect all the state information.

In accordance with one or more embodiments of the present invention, amechanism, such as error logging mechanism 120, is provided todynamically determine the data to log for optimal problemidentification. In the case of hardware detected errors, the processperformed by the error logging mechanism 120 begins by collecting thedata summarized in a hardware error register(s). In the case of firmwareerrors, the process performed by the error logging mechanism 120 beginswith a firmware error reason code. In both cases these indicators (thedata summarized in a hardware register(s) and the error reason code) aretreated as searchable values and are referred to herein collectively aserror codes. These error codes are values stored in a logging referencetable such as that shown below with reference to FIG. 3.

It is to be understood that the block diagram of FIG. 1 is not intendedto indicate that the system 100 is to include all of the componentsshown in FIG. 1. Rather, the system 100 can include any appropriatefewer or additional components not illustrated in FIG. 1 (e.g.,additional memory components, programs, functional blocks, connectionsbetween functional blocks, modules, inputs, outputs, etc.). For example,all or a portion of the error logging mechanism 120 can be located inthe I/O subsystem 114, in the hypervisor 116, and/or in an errordetection mechanism in the HBA 112. Further, the embodiments describedherein with respect to system 100 may be implemented with anyappropriate logic, wherein the logic, as referred to herein, can includeany suitable hardware (e.g., a processor, an embedded controller, or anapplication specific integrated circuit, among others), software (e.g.,an application, among others), firmware, or any suitable combination ofhardware, software, and firmware, in various embodiments.

Turning now to FIG. 2, a service element 102 containing log buffers isgenerally shown in accordance with one or more embodiments of thepresent invention. The service element 102 shown in FIG. 2 includestraditional log buffers 202 and enhanced log buffers 204. Traditionallogging, which includes the use of traditional log buffers 202, can beused as a backup or instead of enhanced logging, which uses enhanced logbuffers 204, for example, when there are no more enhanced log buffers204 available for storing log data or when enhanced logging is otherwisenot available.

Contemporary logging approaches for detected hardware and firmwareerrors, referred to herein as traditional logging, typically utilize avariable number of relatively small sized (e.g., 64 kilobytes (KB)) logbuffers. The variable number of log buffers is typically capped (e.g.,at 5, 7, or 10). Thus, only a limited amount of data can be stored abouteach error due to the limited amount of space in the traditional logbuffers 202. In accordance with one or more embodiments of the presentinvention, by prioritizing the data collection, the data items thoughtto be most important to debugging a particular error can be stored inthe limited amount of space in the traditional log buffers 202.

Also shown in FIG. 2, are the enhanced log buffers 204 which can be usedby the enhanced logging performed by one or more embodiments of theerror logging mechanism described herein. The enhanced log buffers 204shown in FIG. 2 include a large buffer pool 206 shown as being tenmegabytes (MBs) in size and a small buffer pool 208 shown in FIG. 2 asbeing one MB is size. Whether a buffer is selected from the large bufferpool 206 or the small buffer pool 208 depends, for example, on theamount of log data that is collected for a particular error as well asavailability of the buffers.

Two sizes of log buffers are shown in FIG. 2 for ease of description,one skilled in the art will appreciate that any number (3, 10, 100,etc.) of sizes of buffers can be implemented using one more embodimentsof the present invention. The small buffer pool 208 is not limited tohaving buffers sized at 1 MB nor is the large buffer pool 206 limited tohaving buffers sized at 10 MB as these sizes are shown in FIG. 2 asexamples only. In addition to log buffers, other elements (e.g.,processors, network interfaces, etc.) may also be included in thestorage element 102.

Turning now to FIG. 3, block diagram 300 that includes a loggingreference table and logging tables is generally shown in accordance withone or more embodiments of the present invention. In accordance with oneor more embodiments of the present invention, the logging referencetable 302 and the logging tables 304 are stored in memory located on aHBA, such as HBA 112 of FIG. 1.

Upon receipt by the error logging mechanism 120 of an error code fromerror detection and/or correction software being executed for example,by HBA 112 of FIG. 1, the error logging mechanism 120 performs a binarysearch to find the received error code in the logging reference table302. The logging reference table 302 includes error code references forat least a subset of the error codes that can be generated for hardwareand/or firmware errors. In addition, the logging reference table 302 caninclude a default error code reference for use when an error that has anerror code not located in the logging reference table 302 in received bythe error logging mechanism 120. As shown in FIG. 3, the loggingreference table 302 has a table header and is sorted or indexed by errorcode for easy access. In accordance with one or more embodiments of thepresent invention, the table header of the logging reference table 302includes an ASCII name for the table and the length of the table, aswell as an optional pad field so that the size of the table remains on afour byte boundary,

As shown in FIG. 3, each error code reference element in the loggingreference table 302 includes an error code (e.g., a sixteen bit valuerepresenting the error code) and a pointer to a logging table 304 thatincludes entries that are in priority order. In accordance with one ormore embodiments of the present invention the pointer includes anaddress (e.g., a 64 bit address) of a logging table 304. As shown inFIG. 3, each of the entries in a logging table 304 includes adescriptor. In accordance with one or more embodiments, the presentinvention, the table header of a logging table 304 includes an ASCIIname for the table and the length of the table, as well as an optionalpad field so that the size of the table remains on a four byte boundary,

Turning now to FIG. 4, a block diagram 400 that includes logging tables,data structures, and a firmware function in accordance with one or moreembodiments of the present invention. As shown in FIG. 4, each of thedescriptors in a logging table 304 can point to another logging table, adata structure 404, or a firmware function 406 that returns a datastructure 404 or another logging table. In accordance with one or moreembodiments of the present invention, each data structure 404 specifiesan address to collect a data item(s) from and an amount of data tocollect (e.g., a number of bytes to read starting at the address).

In accordance with one or more embodiments of the present invention,upon presentation of an error code to the error logging mechanism 120, abinary search is performed to find the received error code in thelogging reference table 302. Each error code refers to a logging table304 which is used to build a list of data structures to be logged as aresult of the error corresponding to the error code. The logging table304 contains a list of descriptors that point to: another logging table304, a data structure 404, or a firmware function 406 which returns adata structure 404. The descriptors of the data items in the loggingtable 304 are in priority order from highest priority at the start ofthe logging table 304 to lowest priority at the end of the logging table304. When a descriptor points to another logging table 304, the loggingtable 304 being pointed to and its descriptors will be processed beforethe next descriptor in the current logging table 304. If the descriptorpoints to a firmware function 406, the error logging mechanism 120invokes the firmware function 406. A firmware function 406 can beinvoked to inspect control blocks and/or hardware registers for moredetailed identification of priority data to be logged.

An example of a firmware function 406 that can be invoked includes, butis not limited to a function that logs fibre channel request blocks(FCRBs). The HBA has over 800 such control blocks which are used forthread locking and flow control. This example firmware function caninspect the HBA blocks to locate those which are in use and log them.

Another example of a firmware function 406 is a function that is passesa particular operation's unique identifier (these are assigned by thehost OS and passed down to the HBA to uniquely identify requests). Thefunction will scan through several pools of control blocks looking forcontrol blocks associated with the particular operation's uniqueidentifier. Specifically, the control block from the OS is referred toas a queue transfer control block (QTCB) and it contains the uniqueidentifier. Each QTCB will have one or more associated FCRB's and eachFCRB may be associated with one or more I/O control blocks (IOCB's). TheIOCB's have many purposes including executing small computer systeminterface (SCSI) block commands to storage devices or transmitting linkservice requests on the fibre channel link. This example firmwarefunction will locate all control blocks associated with a particularQTCB and log them together for efficient debugging.

The logging tables 304 are tailored to capture the highest priority dataitems for a given error. When the logging code is invoked by a firmwareor hardware error (e.g., by the error logging mechanism 120 receiving anerror code), the first logging table 304 is located via searching thelogging reference table 302. The error logging mechanism 120 processesthe logging table 304 by starting at the first descriptor entry at thetop of the logging table 304. This is the highest priority data. Eachdescriptor is processed in order from the top of the logging table 304to the bottom of the logging table 304, following pointers to additionallogging tables 304 when specified by the descriptor. The result is alinked list of pointers to data structures as shown in FIG. 5.

Turning now to FIG. 5, a linked list 500 of data structures 404 isgenerally shown in accordance with one or more embodiments of thepresent invention. The linked list 500 shown in FIG. 5 and constructedas described above represents an error code specific list of data itemsto log. The data items to be logged are prioritized from highestimportance relative to this error code, to lowest. In accordance withone or more embodiments of the present invention, the error loggingmechanism 120 processes the linked list 500 shown in FIG. 5 in orderstarting with the head 502 of the linked list 500 and ending at the tail504 of the linked list. The head 402 of the linked list 500 is processedfirst because it contains the highest priority information, or dataitem, for debugging the error represented by the error code. Inaccordance with one or more embodiments of the present invention, eachdata structure 404 specified in a list entry may include anaddress/length pair. In accordance with one or more embodiments thelinked list element includes a 64 bit address and 4 byte length. Theaddress/length pair in each data structure 404 is used to identify thestarting location of data to be logged and an amount of data to belogged. In accordance with one or more embodiments of the presentinvention, the data pointed to by the entry must be contiguous inmemory.

In accordance with one or more embodiments of the present invention, theerror logging mechanism 120 is aware of the size constraint for loggingand if it determines there is a chance that the allocated space in theservice element 102 may be overrun, it will stop processing the linkedlist 500. Because the data is collected in priority order, the mostimportant data is collected by one or more embodiments of the presentinvention before the error logging mechanism 120 stops collecting errordata.

Turning now to FIG. 6, a process flow diagram 600 of dynamic logging andprioritization of error incident data is generally shown in accordancewith one or more embodiments of the present invention. All or a portionof the processing shown in FIG. 6 can be implemented by the errorlogging mechanism 120 of FIG. 1. At block 602, an error code is receivedindicating that an error has occurred on the system (e.g., server 106 ofFIG. 1). When an error occurs on the system, log data needs to becollected for problem analysis. At block 604, a check is made todetermine if enhanced logging is enabled. If enhanced logging is notenabled, then processing continues at block 614 with traditional loggingbeing performed and processing ends at block 616.

In accordance with one or more embodiments of the present invention,traditional logging includes building seven independent lists of datastructures which will each fit into a 64 KB buffer. The data is fixedand the elements of the list are in no particular order. There is nodynamic aspect to data collected or priorities assigned for traditionallogging. The logging code will construct the same list of data to belogged for every type of error whether it be hardware or firmwaredetected. In addition, there is no queueing aspect to traditionallogging, if there are no resources available the 64 KB log buffers willbe discarded resulting in loss of data.

The processing at block 604 can also include checking the error code todetermine whether the error type specifically requires traditionallogging. If the error type specifically requires traditional loggingthen processing continues at block 614 and then at block 616. An exampleof an error code that may require traditional logging includes, but isnot limited to a failed recovery scenario such as the following. When anerror occurs and enhanced logging is enabled, that is the path that istaken. The system goes through the normal path of enhanced logging whichcollects the data and attempts to transfer the data to the serviceelement 102. After that process completes, the HBA is then reset by theI/O subsystem. Ordinarily, the HBA hardware will reset successfullyallowing firmware to initialize and indicate readiness to the I/Osubsystem. If the initialization takes longer than a pre-selected periodof time (e.g., 300 milliseconds (ms), 500 ms, 1,000 ms, etc.) the I/Osubsystem assumes the HBA has encountered a potentially unrecoverableerror and will invoke recovery by writing a hardware register on theHBA. When the logging mechanism encounters this error it will forcetraditional logging as it is typically the safest way to collect datawhen an HBA potentially has hardware problems.

If it is determined at block 604 that enhanced logging is enabled and/oroptionally that the error code can be processed by the enhanced logging,processing continues at block 606 with performing data collection. Inaccordance with one or more embodiments of the present invention, asdescribed previously, the error code is looked up in a reference table,such as logging reference table 302 of FIG. 3, to generate a linked listof data items to be collected and a priority order for collecting thedata items. At block 608 it is determined if a log buffer large enoughto accommodate all of the error data that was collected (also referredto herein as a log) is available. In the example shown in FIG. 6, whereonly two sizes of log buffers are available (large and small as show inFIG. 2) for use by the enhanced logging process, a large buffer isrequired to hold all of the error data that was collected at block 606.The determining at block 608 can include attempting to lock a largebuffer. If the attempt at locking the large buffer is successful, thenthe large buffer is available, otherwise if the lock attempt is notsuccessful, a large buffer is not available.

Based on determining, at block 608, that a large buffer in the enhancedlog buffers is available, processing continues at block 612 withtransferring the collected data items, or log data, to the large bufferthat was locked in block 608. The large buffer can be located remotelyfrom the system on a service element, such as service element 102 ofFIG. 1.

Based on determining, at block 608, that a large buffer in the enhancedlog buffers is not available, processing continues at block 610 todetermine whether a small buffer (e.g., a buffer that will not hold allof the error data that was collected at block 606 is available. Thedetermining at block 610 can include attempting to lock a small buffer.If the lock is successful, the small buffer is available. Based ondetermining that a small buffer is available, processing continues atblock 612 with transferring the collected data items, or log data, tothe small buffer (e.g., located on a service element) that was locked inblock 610.

Based on determining that a small block in the enhanced log buffers isnot available, processing continues at block 614 with performingtraditional logging. In accordance with one or more embodiments, wherethe traditional log buffers 202 will only be able to store a subset ofthe data items collected at block 606, the higher priority datacollected at block 606 is stored in the traditional log buffers 202.Thus, the traditional logging performed at block 614 is improved bylogging the data items deemed to be most important to the particularerror code in the traditional log buffers 202.

In accordance with one or more embodiments of the present invention, theenhanced log buffers include a series of buffer pools. Each enhanced logbuffer pool includes a plurality of equal sized buffers. The bufferpools are numbered “1” through “N” where buffer pool 1 contains thesmallest sized buffers and N (which can be larger than two) contains thelargest sized buffers. Due to system constraints, buffer pool N maycontain the least number of buffers and the buffer pool 1 the mostnumber of buffers.

When an error occurs and the log data is defined (e.g., data items arecollected), the system attempts to allocate the smallest sized buffercapable of storing the collected error data. In accordance with one ormore embodiments of the present invention, the size values can bepredetermined for each error code. The system then tries to allocate abuffer from the appropriate buffer pool. If a buffer from that pool isavailable, the system proceeds to use it to log the error data items. Ifnot, the system attempts to select a buffer from the next pool ofsmaller buffers, and then checks again for availability. It repeats thisprocess until a buffer is found. Note that using a smaller buffer thanoriginally desired will result in some log data truncation. If thesystem has gone through all the buffer sizes from all the pools butstill can't find any buffer available, it defaults to the traditionallogging methods.

The process flow diagram of FIG. 6 is not intended to indicate that theoperations of the method 600 are to be executed in any particular order,or that all of the operations of the method 600 are to be included inevery case. Additionally, the method 600 can include any suitable numberof additional operations.

One or more embodiments of the present invention include methods oftransferring the logs, or collected data, to a remote system, such asservice element 102 of FIG. 1. In accordance with one or moreembodiments of the present invention, there is a queue for the logs, orcollected data items, as they are generated. If the remote system (e.g.the service element) is able to accept the log at the time it isgenerated, the log is transferred immediately. If the remote system isbusy or out of resources and cannot accept the log, the log can then bequeued on the local system and transferred at a later time. If anotherlog is generated while logs are currently queued for transfer, the logcan be queued immediately without checking the state of the remotesystem to preserve the order of the log transfers. In accordance withone or more embodiments of the present invention, a separate process isinitiated outside of logging events to handle transferring logs to theremote system when it is ready to accept the logs. The process can beginby periodically polling the remote system to determine when it is readyto receive logs. The logs are then transferred to the remote system inorder of their creation.

Turning now to FIG. 7, a process flow diagram 700 of transferring logdata to a service element is generally shown in accordance with one ormore embodiments of the present invention. All or a portion of theprocessing shown in FIG. 7 can be implemented by the error loggingmechanism 120 of FIG. 1. Processing beings at block 702 when error datahas been collected and is ready to be written to a buffer (e.g., anenhanced log buffer 204 of FIG. 2). The local system (e.g., server 106of FIG. 1) has the ability to transfer a log to a remote system (e.g.,service element 102 of FIG. 1) immediately or at a later time. At block704, a check is made to see if the log (or the collected data) is markedas “force queue.” The local system has the ability to mark a log forunconditional queuing. This results in skipping the check at block 706to determine if the queue is empty. The ability to mark a log forunconditional queueing can allow for debugging utilities and flexibilityin how the logs are handled. If the log is marked as force queue, asdetermined at block 704, processing continues at block 708 withdetermining whether space is available in the queue. If no space isavailable in the queue, the log generation processing aborts. If, asdetermined at block 708, there is space available in the queue, the log,or collected data items, is stored in the queue at block 716 and theprocessing ends at block 718.

At block 706, a check is made to determine whether there are logs thatare already queued and waiting to be transferred. If there are none,then the process proceeds at block 712 to determine if the serviceelement is ready to accept the collected data. In accordance with one ormore embodiments of the present invention, the error logging mechanismcontacts the remote system to see if it is able to receive the log. Ifit is, processing continues at block 714 and the log, or collected data,is transmitted to the remote system and processing completes at block718. If it is determined, at block 712, that the remote system is notavailable (e.g., due to being busy or out of resources), then processingcontinues at block 716 and the log is stored in the queue. No checkingfor space on the queue is needed at this point as the queue was alreadyidentified as being empty at block 706. Processing completes at block718.

As shown in FIG. 7, when a logging event is initiated at block 702 andthe local system (e.g., error logging mechanism 120) has determined atblock 706 that there are currently logs in the queue, it will attempt toqueue the new log at block 716. This process can be used to maintain theorder of the logs being transferred to the remote system. The localsystem then checks if it as room in the queue for the log. If there isroom, as determined at block 708, the log is then queued. If there is noroom, the log has nowhere to be placed and the local system aborts thelog generation at block 710 and can signal that a failure to store thelog has occurred.

The process flow diagram of FIG. 7 is not intended to indicate that theoperations of the method 700 are to be executed in any particular order,or that all of the operations of the method 700 are to be included inevery case. Additionally, the method 700 can include any suitable numberof additional operations.

Turning now to FIG. 8, a method 800 of post processing queued logentries is generally shown in accordance with one or more embodiments ofthe present invention. All or a portion of the processing shown in FIG.8 can be implemented by the error logging mechanism 120 of FIG. 1.

Once the logging event is finished, the local system begins the queuedlog transfer process at block 802. The local system first determines, atblock 804, if there are any logs in the queue. If there are no logsqueued, the process ends at block 812. If it is determined at block 804that there are logs in the queue, the local system checks, at block 806,to see if the remote system is ready to handle the transfer of a queuedlog. If the remote system is not ready, then processing continues atblock 808 with the local system going into a wait period. Once the waitperiod is over, the local system checks again at block 806 to see if theremote system is ready for a log transfer. When, as determined at block806, the remote system is ready for a log transfer, processing continuesat block 810 with the local system transferring the oldest log in thequeue to the remote system. After the transfer is complete, the localsystem begins the processing again at block 804 with determining ifthere are any other logs in the log queue. Once all the logs have beentransferred to the remote system, the process completes at block 812.

The process flow diagram of FIG. 8 is not intended to indicate that theoperations of the method 800 are to be executed in any particular order,or that all of the operations of the method 800 are to be included inevery case. Additionally, the method 800 can include any suitable numberof additional operations.

One or more embodiments of the present invention provide an intelligentmechanism for collecting data for the debug of hardware and firmwareerrors. The content of the data collected is dynamically determinedbased on the indicators presented by hardware registers and/or codevalues provided by the firmware. In accordance with one or moreembodiments of the present invention, the error data collection is doneby dedicated firmware that builds a prioritized linked list of elementsto be collected. This list is specific for the nature of the errordetected. In addition, one or more embodiments of the present inventionprovide a mechanism to dynamically determine at the time of the errorbeing detected what size buffer will be needed. Based on that decision,the system can attempt to allocate a buffer from the appropriate bufferpool. If one cannot be allocated, the system attempts to allocate from apool of smaller size buffers. Using this smaller buffer, some but notall of the log data may be lost. For this reason, highest priority dataare logged first. If none of these buffers are available, the system candefault back to a traditional logging method.

It is to be understood that although this disclosure includes a detaileddescription on cloud computing, implementation of the teachings recitedherein are not limited to a cloud computing environment. Rather,embodiments of the present invention are capable of being implemented inconjunction with any other type of computing environment now known orlater developed.

Cloud computing is a model of service delivery for enabling convenient,on-demand network access to a shared pool of configurable computingresources (e.g., networks, network bandwidth, servers, processing,memory, storage, applications, virtual machines, and services) that canbe rapidly provisioned and released with minimal management effort orinteraction with a provider of the service. This cloud model may includeat least five characteristics, at least three service models, and atleast four deployment models.

Characteristics are as follows:

On-demand self-service: a cloud consumer can unilaterally provisioncomputing capabilities, such as server time and network storage, asneeded automatically without requiring human interaction with theservice's provider.

Broad network access: capabilities are available over a network andaccessed through standard mechanisms that promote use by heterogeneousthin or thick client platforms (e.g., mobile phones, laptops, and PDAs).

Resource pooling: the provider's computing resources are pooled to servemultiple consumers using a multi-tenant model, with different physicaland virtual resources dynamically assigned and reassigned according todemand. There is a sense of location independence in that the consumergenerally has no control or knowledge over the exact location of theprovided resources but may be able to specify location at a higher levelof abstraction (e.g., country, state, or datacenter).

Rapid elasticity: capabilities can be rapidly and elasticallyprovisioned, in some cases automatically, to quickly scale out andrapidly released to quickly scale in. To the consumer, the capabilitiesavailable for provisioning often appear to be unlimited and can bepurchased in any quantity at any time.

Measured service: cloud systems automatically control and optimizeresource use by leveraging a metering capability at some level ofabstraction appropriate to the type of service (e.g., storage,processing, bandwidth, and active user accounts). Resource usage can bemonitored, controlled, and reported, providing transparency for both theprovider and consumer of the utilized service.

Service Models are as follows:

Software as a Service (SaaS): the capability provided to the consumer isto use the provider's applications running on a cloud infrastructure.The applications are accessible from various client devices through athin client interface such as a web browser (e.g., web-based e-mail).The consumer does not manage or control the underlying cloudinfrastructure including network, servers, operating systems, storage,or even individual application capabilities, with the possible exceptionof limited user-specific application configuration settings.

Platform as a Service (PaaS): the capability provided to the consumer isto deploy onto the cloud infrastructure consumer-created or acquiredapplications created using programming languages and tools supported bythe provider. The consumer does not manage or control the underlyingcloud infrastructure including networks, servers, operating systems, orstorage, but has control over the deployed applications and possiblyapplication hosting environment configurations.

Infrastructure as a Service (IaaS): the capability provided to theconsumer is to provision processing, storage, networks, and otherfundamental computing resources where the consumer is able to deploy andrun arbitrary software, which can include operating systems andapplications. The consumer does not manage or control the underlyingcloud infrastructure but has control over operating systems, storage,deployed applications, and possibly limited control of select networkingcomponents (e.g., host firewalls).

Deployment Models are as follows:

Private cloud: the cloud infrastructure is operated solely for anorganization. It may be managed by the organization or a third party andmay exist on-premises or off-premises.

Community cloud: the cloud infrastructure is shared by severalorganizations and supports a specific community that has shared concerns(e.g., mission, security requirements, policy, and complianceconsiderations). It may be managed by the organizations or a third partyand may exist on-premises or off-premises.

Public cloud: the cloud infrastructure is made available to the generalpublic or a large industry group and is owned by an organization sellingcloud services.

Hybrid cloud: the cloud infrastructure is a composition of two or moreclouds (private, community, or public) that remain unique entities butare bound together by standardized or proprietary technology thatenables data and application portability (e.g., cloud bursting forload-balancing between clouds).

A cloud computing environment is service oriented with a focus onstatelessness, low coupling, modularity, and semantic interoperability.At the heart of cloud computing is an infrastructure that includes anetwork of interconnected nodes.

Referring now to FIG. 9, illustrative cloud computing environment 50 isdepicted. As shown, cloud computing environment 50 includes one or morecloud computing nodes 10 with which local computing devices used bycloud consumers, such as, for example, personal digital assistant (PDA)or cellular telephone 54A, desktop computer 54B, laptop computer 54C,and/or automobile computer system 54N may communicate. Nodes 10 maycommunicate with one another. They may be grouped (not shown) physicallyor virtually, in one or more networks, such as Private, Community,Public, or Hybrid clouds as described hereinabove, or a combinationthereof. This allows cloud computing environment 50 to offerinfrastructure, platforms and/or software as services for which a cloudconsumer does not need to maintain resources on a local computingdevice. It is understood that the types of computing devices 54A-N shownin FIG. 9 are intended to be illustrative only and that computing nodes10 and cloud computing environment 50 can communicate with any type ofcomputerized device over any type of network and/or network addressableconnection (e.g., using a web browser).

Referring now to FIG. 10, a set of functional abstraction layersprovided by cloud computing environment 50 (FIG. 9) is shown. It shouldbe understood in advance that the components, layers, and functionsshown in FIG. 10 are intended to be illustrative only and embodiments ofthe invention are not limited thereto. As depicted, the following layersand corresponding functions are provided:

Hardware and software layer 60 includes hardware and softwarecomponents. Examples of hardware components include: mainframes 61; RISC(Reduced Instruction Set Computer) architecture based servers 62;servers 63; blade servers 64; storage devices 65; and networks andnetworking components 66. In some embodiments, software componentsinclude network application server software 67 and database software 68.

Virtualization layer 70 provides an abstraction layer from which thefollowing examples of virtual entities may be provided: virtual servers71; virtual storage 72; virtual networks 73, including virtual privatenetworks; virtual applications and operating systems 74; and virtualclients 75.

In one example, management layer 80 may provide the functions describedbelow. Resource provisioning 81 provides dynamic procurement ofcomputing resources and other resources that are utilized to performtasks within the cloud computing environment. Metering and Pricing 82provide cost tracking as resources are utilized within the cloudcomputing environment, and billing or invoicing for consumption of theseresources. In one example, these resources may include applicationsoftware licenses. Security provides identity verification for cloudconsumers and tasks, as well as protection for data and other resources.User portal 83 provides access to the cloud computing environment forconsumers and system administrators. Service level management 84provides cloud computing resource allocation and management such thatrequired service levels are met. Service Level Agreement (SLA) planningand fulfillment 85 provide pre-arrangement for, and procurement of,cloud computing resources for which a future requirement is anticipatedin accordance with an SLA.

Workloads layer 90 provides examples of functionality for which thecloud computing environment may be utilized. Examples of workloads andfunctions which may be provided from this layer include: mapping andnavigation 91; software development and lifecycle management 92; virtualclassroom education delivery 93; data analytics processing 94;transaction processing 95; and hardware and firmware error datacollection and logging 96.

It is understood that one or more embodiments of the present inventionare capable of being implemented in conjunction with any type ofcomputing environment now known or later developed.

Turning now to FIG. 11, a computer system for buffer overflow trappingis generally shown in accordance with one or more embodiments of thepresent invention. The methods described herein can be implemented inhardware, software (e.g., firmware), or a combination thereof. In one ormore exemplary embodiments of the present invention, the methodsdescribed herein are implemented in hardware as part of themicroprocessor of a special or general-purpose digital computer, such asa personal computer, workstation, minicomputer, or mainframe computer.The system 1100 therefore may include general-purpose computer ormainframe 1101 capable of running multiple instances of an O/Ssimultaneously.

In one or more exemplary embodiments of the present invention, in termsof hardware architecture, as shown in FIG. 11, the computer 1101includes one or more processors 1105, memory 1110 coupled to a memorycontroller 1115, and one or more input and/or output (I/O) devices 1140,1145 (or peripherals) that are communicatively coupled via a localinput/output controller 1135. The input/output controller 1135 can be,for example but not limited to, one or more buses or other wired orwireless connections, as is known in the art. The input/outputcontroller 1135 may have additional elements, which are omitted forsimplicity, such as controllers, buffers (caches), drivers, repeaters,and receivers, to enable communications. Further, the local interfacemay include address, control, and/or data connections to enableappropriate communications among the aforementioned components. Theinput/output controller 1135 may include a plurality of sub-channelsconfigured to access the output devices 1140 and 1145. The sub-channelsmay include fiber-optic communications ports.

The processor 1105 is a hardware device for executing software,particularly that stored in storage 1120, such as cache storage, ormemory 1110. The processor 1105 can be any custom made or commerciallyavailable processor, a central processing unit (CPU), an auxiliaryprocessor among several processors associated with the computer 1101, asemiconductor based microprocessor (in the form of a microchip or chipset), a macroprocessor, or generally any device for executinginstructions.

The memory 1110 can include any one or combination of volatile memoryelements (e.g., random access memory (RAM, such as DRAM, SRAM, SDRAM,etc.)) and nonvolatile memory elements (e.g., ROM, erasable programmableread only memory (EPROM), electronically erasable programmable read onlymemory (EEPROM), programmable read only memory (PROM), tape, compactdisc read only memory (CD-ROM), disk, diskette, cartridge, cassette orthe like, etc.). Moreover, the memory 1110 may incorporate electronic,magnetic, optical, and/or other types of storage media. Note that thememory 1110 can have a distributed architecture, where variouscomponents are situated remote from one another, but can be accessed bythe processor 1105.

The instructions in memory 1110 may include one or more separateprograms, each of which comprises an ordered listing of executableinstructions for implementing logical functions. In the example of FIG.11, the instructions in the memory 1110 a suitable operating system (OS)1111. The operating system 1111 essentially controls the execution ofother computer programs and provides scheduling, input-output control,file and data management, memory management, and communication controland related services.

In accordance with one or more embodiments of the present invention, thememory 1110 may include multiple logical partitions (LPARs) each runningan instance of an operating system. The LPARs may be managed by ahypervisor, which may be a program stored in memory 1110 and executed bythe processor 1105.

In one or more exemplary embodiments of the present invention, aconventional keyboard 1150 and mouse 1155 can be coupled to theinput/output controller 1135. Other output devices such as the I/Odevices 1140, 1145 may include input devices, for example but notlimited to a printer, a scanner, microphone, and the like. Finally, theI/O devices 1140, 1145 may further include devices that communicate bothinputs and outputs, for instance but not limited to, a network interfacecard (NIC) or modulator/demodulator (for accessing other files, devices,systems, or a network), a radio frequency (RF) or other transceiver, atelephonic interface, a bridge, a router, and the like. The system 1100can further include a display controller 1125 coupled to a display 1130.

In one or more exemplary embodiments of the present invention, thesystem 1100 can further include a network interface 1160 for coupling toa network 1165. The network 1165 can be an IP-based network forcommunication between the computer 1101 and any external server, clientand the like via a broadband connection. The network 1165 transmits andreceives data between the computer 1101 and external systems. In anexemplary embodiment, network 1165 can be a managed IP networkadministered by a service provider. The network 1165 may be implementedin a wireless fashion, e.g., using wireless protocols and technologies,such as WiFi, WiMax, etc. The network 1165 can also be a packet-switchednetwork such as a local area network, wide area network, metropolitanarea network, Internet network, or other similar type of networkenvironment. The network 1165 may be a fixed wireless network, awireless local area network (LAN), a wireless wide area network (WAN) apersonal area network (PAN), a virtual private network (VPN), intranetor other suitable network system and includes equipment for receivingand transmitting signals.

If the computer 1101 is a PC, workstation, intelligent device or thelike, the instructions in the memory 1110 may further include a basicinput output system (BIOS) (omitted for simplicity). The BIOS is a setof essential software routines that initialize and test hardware atstartup, start the OS 1111, and support the transfer of data among thehardware devices. The BIOS is stored in ROM so that the BIOS can beexecuted when the computer 1101 is activated.

When the computer 1101 is in operation, the processor 1105 is configuredto execute instructions stored within the memory 1110, to communicatedata to and from the memory 1110, and to generally control operations ofthe computer 1101 pursuant to the instructions. In accordance with oneor more embodiments of the present invention, computer 1101 is anexample of a cloud computing node 10 of FIG. 9.

Various embodiments of the invention are described herein with referenceto the related drawings. Alternative embodiments of the invention can bedevised without departing from the scope of this invention. Variousconnections and positional relationships (e.g., over, below, adjacent,etc.) are set forth between elements in the following description and inthe drawings. These connections and/or positional relationships, unlessspecified otherwise, can be direct or indirect, and the presentinvention is not intended to be limiting in this respect. Accordingly, acoupling of entities can refer to either a direct or an indirectcoupling, and a positional relationship between entities can be a director indirect positional relationship. Moreover, the various tasks andprocess steps described herein can be incorporated into a morecomprehensive procedure or process having additional steps orfunctionality not described in detail herein.

One or more of the methods described herein can be implemented with anyor a combination of the following technologies, which are each wellknown in the art: a discreet logic circuit(s) having logic gates forimplementing logic functions upon data signals, an application specificintegrated circuit (ASIC) having appropriate combinational logic gates,a programmable gate array(s) (PGA), a field programmable gate array(FPGA), etc.

For the sake of brevity, conventional techniques related to making andusing aspects of the invention may or may not be described in detailherein. In particular, various aspects of computing systems and specificcomputer programs to implement the various technical features describedherein are well known. Accordingly, in the interest of brevity, manyconventional implementation details are only mentioned briefly herein orare omitted entirely without providing the well-known system and/orprocess details.

In some embodiments, various functions or acts can take place at a givenlocation and/or in connection with the operation of one or moreapparatuses or systems. In some embodiments, a portion of a givenfunction or act can be performed at a first device or location, and theremainder of the function or act can be performed at one or moreadditional devices or locations.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting. As used herein, thesingular forms “a”, “an” and “the” are intended to include the pluralforms as well, unless the context clearly indicates otherwise. It willbe further understood that the terms “comprises” and/or “comprising,”when used in this specification, specify the presence of statedfeatures, integers, steps, operations, elements, and/or components, butdo not preclude the presence or addition of one or more other features,integers, steps, operations, element components, and/or groups thereof.

The corresponding structures, materials, acts, and equivalents of allmeans or step plus function elements in the claims below are intended toinclude any structure, material, or act for performing the function incombination with other claimed elements as specifically claimed. Thepresent disclosure has been presented for purposes of illustration anddescription but is not intended to be exhaustive or limited to the formdisclosed. Many modifications and variations will be apparent to thoseof ordinary skill in the art without departing from the scope and spiritof the disclosure. The embodiments were chosen and described in order tobest explain the principles of the disclosure and the practicalapplication, and to enable others of ordinary skill in the art tounderstand the disclosure for various embodiments with variousmodifications as are suited to the particular use contemplated.

The diagrams depicted herein are illustrative. There can be manyvariations to the diagram or the steps (or operations) described thereinwithout departing from the spirit of the disclosure. For instance, theactions can be performed in a differing order or actions can be added,deleted or modified. Also, the term “coupled” describes having a signalpath between two elements and does not imply a direct connection betweenthe elements with no intervening elements/connections therebetween. Allof these variations are considered a part of the present disclosure.

The following definitions and abbreviations are to be used for theinterpretation of the claims and the specification. As used herein, theterms “comprises,” “comprising,” “includes,” “including,” “has,”“having,” “contains” or “containing,” or any other variation thereof,are intended to cover a non-exclusive inclusion. For example, acomposition, a mixture, process, method, article, or apparatus thatcomprises a list of elements is not necessarily limited to only thoseelements but can include other elements not expressly listed or inherentto such composition, mixture, process, method, article, or apparatus.

Additionally, the term “exemplary” is used herein to mean “serving as anexample, instance or illustration.” Any embodiment or design describedherein as “exemplary” is not necessarily to be construed as preferred oradvantageous over other embodiments or designs. The terms “at least one”and “one or more” are understood to include any integer number greaterthan or equal to one, i.e. one, two, three, four, etc. The terms “aplurality” are understood to include any integer number greater than orequal to two, i.e. two, three, four, five, etc. The term “connection”can include both an indirect “connection” and a direct “connection.”

The terms “about,” “substantially,” “approximately,” and variationsthereof, are intended to include the degree of error associated withmeasurement of the particular quantity based upon the equipmentavailable at the time of filing the application. For example, “about”can include a range of ±8% or 5%, or 2% of a given value.

The present invention may be a system, a method, and/or a computerprogram product at any possible technical detail level of integration.The computer program product may include a computer readable storagemedium (or media) having computer readable program instructions thereonfor causing a processor to carry out aspects of the present invention.

The computer readable storage medium can be a tangible device that canretain and store instructions for use by an instruction executiondevice. The computer readable storage medium may be, for example, but isnot limited to, an electronic storage device, a magnetic storage device,an optical storage device, an electromagnetic storage device, asemiconductor storage device, or any suitable combination of theforegoing. A non-exhaustive list of more specific examples of thecomputer readable storage medium includes the following: a portablecomputer diskette, a hard disk, a random access memory (RAM), aread-only memory (ROM), an erasable programmable read-only memory (EPROMor Flash memory), a static random access memory (SRAM), a portablecompact disc read-only memory (CD-ROM), a digital versatile disk (DVD),a memory stick, a floppy disk, a mechanically encoded device such aspunch-cards or raised structures in a groove having instructionsrecorded thereon, and any suitable combination of the foregoing. Acomputer readable storage medium, as used herein, is not to be construedas being transitory signals per se, such as radio waves or other freelypropagating electromagnetic waves, electromagnetic waves propagatingthrough a waveguide or other transmission media (e.g., light pulsespassing through a fiber-optic cable), or electrical signals transmittedthrough a wire.

Computer readable program instructions described herein can bedownloaded to respective computing/processing devices from a computerreadable storage medium or to an external computer or external storagedevice via a network, for example, the Internet, a local area network, awide area network and/or a wireless network. The network may comprisecopper transmission cables, optical transmission fibers, wirelesstransmission, routers, firewalls, switches, gateway computers and/oredge servers. A network adapter card or network interface in eachcomputing/processing device receives computer readable programinstructions from the network and forwards the computer readable programinstructions for storage in a computer readable storage medium withinthe respective computing/processing device.

Computer readable program instructions for carrying out operations ofthe present invention may be assembler instructions,instruction-set-architecture (ISA) instructions, machine instructions,machine dependent instructions, microcode, firmware instructions,state-setting data, configuration data for integrated circuitry, oreither source code or object code written in any combination of one ormore programming languages, including an object oriented programminglanguage such as Smalltalk, C++, or the like, and procedural programminglanguages, such as the “C” programming language or similar programminglanguages. The computer readable program instructions may executeentirely on the user's computer, partly on the user's computer, as astand-alone software package, partly on the user's computer and partlyon a remote computer or entirely on the remote computer or server. Inthe latter scenario, the remote computer may be connected to the user'scomputer through any type of network, including a local area network(LAN) or a wide area network (WAN), or the connection may be made to anexternal computer (for example, through the Internet using an InternetService Provider). In some embodiments, electronic circuitry including,for example, programmable logic circuitry, field-programmable gatearrays (FPGA), or programmable logic arrays (PLA) may execute thecomputer readable program instruction by utilizing state information ofthe computer readable program instructions to personalize the electroniccircuitry, in order to perform aspects of the present invention.

Aspects of the present invention are described herein with reference toflowchart illustrations and/or block diagrams of methods, apparatus(systems), and computer program products according to embodiments of theinvention. It will be understood that each block of the flowchartillustrations and/or block diagrams, and combinations of blocks in theflowchart illustrations and/or block diagrams, can be implemented bycomputer readable program instructions.

These computer readable program instructions may be provided to aprocessor of a general purpose computer, special purpose computer, orother programmable data processing apparatus to produce a machine, suchthat the instructions, which execute via the processor of the computeror other programmable data processing apparatus, create means forimplementing the functions/acts specified in the flowchart and/or blockdiagram block or blocks. These computer readable program instructionsmay also be stored in a computer readable storage medium that can directa computer, a programmable data processing apparatus, and/or otherdevices to function in a particular manner, such that the computerreadable storage medium having instructions stored therein comprises anarticle of manufacture including instructions which implement aspects ofthe function/act specified in the flowchart and/or block diagram blockor blocks.

The computer readable program instructions may also be loaded onto acomputer, other programmable data processing apparatus, or other deviceto cause a series of operational steps to be performed on the computer,other programmable apparatus or other device to produce a computerimplemented process, such that the instructions which execute on thecomputer, other programmable apparatus, or other device implement thefunctions/acts specified in the flowchart and/or block diagram block orblocks.

The flowchart and block diagrams in the Figures illustrate thearchitecture, functionality, and operation of possible implementationsof systems, methods, and computer program products according to variousembodiments of the present invention. In this regard, each block in theflowchart or block diagrams may represent a module, segment, or portionof instructions, which comprises one or more executable instructions forimplementing the specified logical function(s). In some alternativeimplementations, the functions noted in the blocks may occur out of theorder noted in the Figures. For example, two blocks shown in successionmay, in fact, be executed substantially concurrently, or the blocks maysometimes be executed in the reverse order, depending upon thefunctionality involved. It will also be noted that each block of theblock diagrams and/or flowchart illustration, and combinations of blocksin the block diagrams and/or flowchart illustration, can be implementedby special purpose hardware-based systems that perform the specifiedfunctions or acts or carry out combinations of special purpose hardwareand computer instructions.

The descriptions of the various embodiments of the present inventionhave been presented for purposes of illustration but are not intended tobe exhaustive or limited to the embodiments disclosed. Manymodifications and variations will be apparent to those of ordinary skillin the art without departing from the scope and spirit of the describedembodiments. The terminology used herein was chosen to best explain theprinciples of the embodiments, the practical application or technicalimprovement over technologies found in the marketplace, or to enableothers of ordinary skill in the art to understand the embodimentsdescribed herein.

What is claimed is:
 1. A method comprising: receiving an error codedescribing a computer hardware or firmware error; receiving a list ofdata items to be collected to assist in correcting the error, thecontents of the list selected based at least in part on the error code,and the contents of the list in priority order from a highest prioritydata item to a lowest priority data item; collecting the data items inthe list; selecting a buffer to store the collected data items; andtransmitting at least a subset of the collected data items to be writtento the buffer, wherein all of the collected data items are transmittedto the buffer when the buffer is large enough to hold all of the dataitems in the list, and a subset of the collected data items aretransmitted to the buffer in priority order starting with the highestpriority data item when the buffer is not large enough to hold all ofthe data in the list.
 2. The method of claim 1, wherein building a listof data items to be collected comprises: accessing a logging tablecorresponding to the error, the logging table comprising a plurality ofentries in priority order, each entry pointing to one selected from thegroup consisting of another logging table, a data item, and a firmwarefunction that returns a data item, the accessing following the priorityorder to build the list of data items.
 3. The method of claim 1, whereinthe list is organized as a linked list.
 4. The method of claim 1,wherein an amount of storage space required to hold the data items inthe list is determined based on the error code and the selecting abuffer is based at least in part on the amount of storage space requiredto hold the data items in the list.
 5. The method of claim 1, whereinthe buffer is selected from a pool of buffers having a variety of sizesand the buffer is the largest buffer available in the pool of buffers.6. The method of claim 5, where the buffer is not large enough to holdall of the data in the list.
 7. The method of claim 6, wherein multiplebuffers are selected to store the collected data items.
 8. The method ofclaim 1, wherein the buffer is selected from a pool of buffers having avariety of sizes and the buffer is the smallest buffer available in thepool of buffers that can hold all of the data items in the list.
 9. Themethod of claim 1, wherein the buffer is located on a remote system andthe method further comprises subsequent to the selecting, determiningthat the remote system is currently unavailable and queuing thecollected data until the remote system becomes available, wherein theselecting is performed subsequent to the remote system becomingavailable.
 10. A system comprising: one or more processors for executingcomputer readable instructions, the computer readable instructionscontrolling the one or more processors to perform operations comprising:receiving an error code describing a computer hardware or firmwareerror; receiving a list of data items to be collected to assist incorrecting the error, the contents of the list selected based at leastin part on the error code, and the contents of the list in priorityorder from a highest priority data item to a lowest priority data item;collecting the data items in the list; selecting a buffer to store thecollected data items; and transmitting at least a subset of thecollected data items to be written to the buffer, wherein all of thecollected data items are transmitted to the buffer when the buffer islarge enough to hold all of the data items in the list, and a subset ofthe collected data items are transmitted to the buffer in priority orderstarting with the highest priority data item when the buffer is notlarge enough to hold all of the data in the list.
 11. The system ofclaim 10, wherein building a list of data items to be collectedcomprises: accessing a logging table corresponding to the error, thelogging table comprising a plurality of entries in priority order, eachentry pointing to one selected from the group consisting of anotherlogging table, a data item, and a firmware function that returns a dataitem, the accessing following the priority order to build the list ofdata items.
 12. The system of claim 10, wherein an amount of storagespace required to hold the data items in the list is determined based onthe error code and the selecting a buffer is based at least in part onthe amount of storage space required to hold the data items in the list.13. The system of claim 10, wherein the buffer is selected from a poolof buffers having a variety of sizes and the buffer is the largestbuffer available in the pool of buffers.
 14. The system of claim 13,where the buffer is not large enough to hold all of the data in thelist.
 15. The system of claim 14, wherein multiple buffers are selectedto store the collected data items.
 16. The system of claim 10, whereinthe buffer is selected from a pool of buffers having a variety of sizesand the buffer is the smallest buffer available in the pool of buffersthat can hold all of the data items in the list.
 17. The system of claim10, wherein the buffer is located on a remote system and the operationsfurther comprise, subsequent to the selecting, determining that theremote system is currently unavailable and queuing the collected datauntil the remote system becomes available, wherein the selecting isperformed subsequent to the remote system becoming available.
 18. Acomputer program product comprising a computer readable storage mediumhaving program instructions embodied therewith, the program instructionsexecutable by a processor to cause the processor to perform operationscomprising: receiving an error code describing a computer hardware orfirmware error; receiving a list of data items to be collected to assistin correcting the error, the contents of the list selected based atleast in part on the error code, and the contents of the list inpriority order from a highest priority data item to a lowest prioritydata item; collecting the data items in the list; selecting a buffer tostore the collected data items; and transmitting at least a subset ofthe collected data items to be written to the buffer, wherein all of thecollected data items are transmitted to the buffer when the buffer islarge enough to hold all of the data items in the list, and a subset ofthe collected data items are transmitted to the buffer in priority orderstarting with the highest priority data item when the buffer is notlarge enough to hold all of the data in the list.
 19. The computerprogram product of claim 18, wherein building a list of data items to becollected comprises: accessing a logging table corresponding to theerror, the logging table comprising a plurality of entries in priorityorder, each entry pointing to one selected from the group consisting ofanother logging table, a data item, and a firmware function that returnsa data item, the accessing following the priority order to build thelist of data items.
 20. The computer program product of claim 18,wherein the buffer is located on a remote system and the method furthercomprises subsequent to the selecting, determining that the remotesystem is currently unavailable and queuing the collected data until theremote system becomes available.